Buying or Idling?

I've never been a fan of selling stock for the sake of selling it. The hurdle rate after taxes for the right to simply start over from scratch is a high bar. Outside of consumption or intentionally de-leveraging a concentrated position, staying put tends to be more fruitful. 

So if you own good companies that you're going to hold onto for a long time, it's a reasonable question to ask when would be a good time to buy more of it.

If you own a stock that has sold off 50% from recent highs, and you're not actively buying at those levels, it probably tells a story that you either a.) already own too much and can't stomach the additional risk or b.) never really had a good reason to own it in the first place. Because in reality, it's a gift to be able to buy a good stock that's at a substantially lower price than it was months earlier. If you liked buying it at $200/share, you should love buying it at $100/share.

I own several positions that have been absolutely hammered over the past three months. I've been buying incrementally on the way down. And buying knowing full well that the stocks could be cut in half from here, at which point I'll buy a little more.

If you're not buying more of a stock you own that's 50% off over the past few months, perhaps you need to revisit why you own it in the first place.